test_outer = ->
  run_test [
    "outer(a,b)",
    "a*b",

    "outer(a,[b1,b2])",
    "[a*b1,a*b2]",

    "outer([a1,a2],b)",
    "[a1*b,a2*b]",

    "H33=hilbert(3)",
    "",

    "H44=hilbert(4)",
    "",

    "H55=hilbert(5)",
    "",

    "H3344=outer(H33,H44)",
    "",

    "H4455=outer(H44,H55)",
    "",

    "H33444455=outer(H33,H44,H44,H55)",
    "",

    "simplify(inner(H3344,H4455)-contract(H33444455,4,5))",
    "0",
  ]
